Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered structurally. The description adds nothing beyond that — no note on what is returned, whether missing documents error out, or how the playbook/run/slug hierarchy resolves. With annotations carrying the burden, this still leaves the description thin.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The single sentence is efficient and front-loaded, but it is under-specified rather than genuinely concise — there is simply very little content to waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

This is a read tool with three required hierarchical identifiers and no output schema, so the description should clarify what the document content looks like and how sections are selected. It covers none of that, leaving the agent to guess the return shape and the purpose of section_id.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all four parameters (slug, run_id, playbook_id, section_id) are documented in the schema itself. The description adds no extra meaning, which is acceptable given the high coverage baseline of 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

"Read a canvas document" restates the tool name and title without adding a specific verb+scope combination. It does not distinguish the tool from siblings like list_canvas, write_canvas, or get_playbook, so an agent gets no signal about what makes this a read of a single canvas versus a listing.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool versus list_canvas or write_canvas, and no mention of prerequisites such as needing an existing run_id or slug. The agent must infer usage entirely from the name.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.